Renal organ, of Ascidians, [54];
of Fishes—see Kidneys
Reproductive organs, of Hemichordata, [16], [25];
of Tunicata, [55], [67], [76], [93], [97], [105];
of Amphioxus, [129];
of Fishes, [402] f., [400], [403]
Respiration, mechanism of, [288]
Respiratory organs—Elasmobranchii, [276], [278];